The present invention relates to a binding device which causes legs of a bind member to pass through punched holes formed in sheets to be bound, and forms the legs into a ring-like shape, thereby binding the sheets.
For example, plural copied sheets are bound and then distributed during a meeting or presentation. Generally, staples are used as a means for binding sheets. However, this means has a disadvantage in that a spread portion of the bound sheets is difficult to see. Means for bonding together end faces of sheets using a hot melt adhesive is also known. However, the means which uses a hot melt adhesive in binding has a problem in that the adhesive must be cooled after beating and hence the binding process requires a prolonged time period.
A binding device which allows sheets to be completely spread and in which the binding process can be rapidly performed is known. In the device, as shown in FIG. 12(a), a bind member 22 is used in which plural U-like pieces 21 perpendicularly project from a straight portion 20 at regular intervals. The U-like pieces 21 are passed through punched holes 24 which are previously formed along edges of sheets 23, respectively. The portions projecting from the punched holes 24 are bent by a bending device as shown in FIG. 12(b) to form the pieces into a ring-like shape, whereby the sheets 23 are bound. When sheets are bound by such a binding device, facing pages can be spread 180 degrees, and the whole face of each page can be seen.
However, the binding device has problems as follows. The bind member 22 itself has the plural U-like pieces 21 which are previously shaped, and the length of the member is chosen to correspond to a length of a side of a particular size sheet 23 (for example a B5 size, A4 size, or the like). Therefore, each bind member is bulky. When multiple bind members are prepared, a large space is required, and the bind members may become entangled with one another and hence difficult to handle. Furthermore, the production cost of one bind member is high. Therefore, the work of binding a number of sheets while grouping the sheets into many sets is cumbersome and costly.